<template>
	<s-layout navbar="normal" :leftWidth="0" :rightWidth="0" tools="search" :defaultSearch="state.keyword"
		@search="onSearch">
		<!-- 筛选 -->
		<su-sticky bgColor="#fff">
			<view class="ss-flex">
				<view class="ss-flex-1">
					<su-tabs :list="state.tabList" :scrollable="false" @change="onTabsChange"
                   :current="state.currentTab" />
				</view>
				<view class="list-icon" @tap="state.iconStatus = !state.iconStatus">
					<text v-if="state.iconStatus" class="sicon-goods-list" />
					<text v-else class="sicon-goods-card" />
				</view>
			</view>
		</su-sticky>

		<!-- 弹窗 -->
		<su-popup :show="state.showFilter" type="top" round="10" :space="sys_navBar + 38" backgroundColor="#F6F6F6"
			:zIndex="10" @close="state.showFilter = false">
			<view class="filter-list-box">
				<view class="filter-item" v-for="(item, index) in state.tabList[state.currentTab].list"
					:key="item.value" :class="[{ 'filter-item-active': index === state.curFilter }]"
					@tap="onFilterItem(index)">
					{{ item.label }}
				</view>
			</view>
		</su-popup>

    <!-- 情况一：单列布局 -->
		<view v-if="state.iconStatus && state.pagination.total > 0" class="goods-list ss-m-t-20">
			<view class="ss-p-l-20 ss-p-r-20 ss-m-b-20" v-for="item in state.pagination.list" :key="item.id">
				<s-goods-column
          class=""
          size="lg"
          :data="item"
          :topRadius="10"
          :bottomRadius="10"
					@click="sheep.$router.go('/pages/goods/index', { id: item.id })"
        />
			</view>
		</view>
    <!-- 情况二：双列布局 -->
    <view v-if="!state.iconStatus && state.pagination.total > 0"
			class="ss-flex ss-flex-wrap ss-p-x-20 ss-m-t-20 ss-col-top">
			<view class="goods-list-box">
				<view class="left-list" v-for="item in state.leftGoodsList" :key="item.id">
					<s-goods-column
            class="goods-md-box"
            size="md"
            :data="item"
            :topRadius="10"
            :bottomRadius="10"
						@click="sheep.$router.go('/pages/goods/index', { id: item.id })"
						@getHeight="mountMasonry($event, 'left')"
          >
						<template v-slot:cart>
							<button class="ss-reset-button cart-btn" />
						</template>
					</s-goods-column>
				</view>
			</view>
			<view class="goods-list-box">
				<view class="right-list" v-for="item in state.rightGoodsList" :key="item.id">
					<s-goods-column
            class="goods-md-box"
            size="md"
            :topRadius="10"
            :bottomRadius="10"
            :data="item"
						@click="sheep.$router.go('/pages/goods/index', { id: item.id })"
						@getHeight="mountMasonry($event, 'right')"
          >
						<template v-slot:cart>
							<button class="ss-reset-button cart-btn" />
						</template>
					</s-goods-column>
				</view>
			</view>
		</view>
		<uni-load-more v-if="state.pagination.total > 0" :status="state.loadStatus" :content-text="{
        contentdown: '上拉加载更多',
      }" @tap="loadMore" />
		<s-empty v-if="state.pagination.total === 0" icon="/static/soldout-empty.png" text="暂无商品" />
	</s-layout>
</template>

<script setup>
	import { reactive } from 'vue';
	import { onLoad, onReachBottom } from '@dcloudio/uni-app';
	import sheep from '@/sheep';
	import _ from 'lodash';
  import { resetPagination } from '@/sheep/util';
  import SpuApi from '@/sheep/api/product/spu';

	const sys_navBar = sheep.$platform.navbar;
	const emits = defineEmits(['close', 'change']);

	const state = reactive({
		pagination: {
			list: [],
      total: 0,
      pageNo: 1,
			pageSize: 6,
		},
		currentSort: undefined,
		currentOrder: undefined,
		currentTab: 0, // 当前选中的 tab
		curFilter: 0, // 当前选中的 list 筛选项
		showFilter: false,
		iconStatus: false, // true - 单列布局；false - 双列布局
    keyword: '',
    categoryId: 0,
		tabList: [{
				name: '综合推荐',
				list: [{
						label: '综合推荐'
					},
					{
						label: '价格升序',
						sort: 'price',
						order: true,
					},
					{
						label: '价格降序',
						sort: 'price',
						order: false,
					},
				],
			},
			{
				name: '销量',
				sort: 'salesCount',
				order: false
			},
			{
				name: '新品优先',
				value: 'createTime',
        order: false
			},
		],
		loadStatus: '',
		leftGoodsList: [], // 双列布局 - 左侧商品
		rightGoodsList: [], // 双列布局 - 右侧商品
	});

	// 加载瀑布流
	let count = 0;
	let leftHeight = 0;
	let rightHeight = 0;

  // 处理双列布局 leftGoodsList + rightGoodsList
	function mountMasonry(height = 0, where = 'left') {
		if (!state.pagination.list[count]) {
      return;
    }

		if (where === 'left') {
			leftHeight += height;
		} else {
			rightHeight += height;
		}
		if (leftHeight <= rightHeight) {
			state.leftGoodsList.push(state.pagination.list[count]);
		} else {
			state.rightGoodsList.push(state.pagination.list[count]);
		}
		count++;
	}

  // 清空列表
	function emptyList() {
    resetPagination(state.pagination);
    state.leftGoodsList = [];
		state.rightGoodsList = [];
		count = 0;
		leftHeight = 0;
		rightHeight = 0;
	}

	// 搜索
	function onSearch(e) {
		state.keyword = e;
		emptyList();
		getList(state.currentSort, state.currentOrder);
	}

	// 点击
	function onTabsChange(e) {
    // 如果点击的是【综合推荐】，则直接展开或者收起筛选项
		if (state.tabList[e.index].list) {
			state.currentTab = e.index;
			state.showFilter = !state.showFilter;
			return;
		}
    state.showFilter = false;

    // 如果点击的是【销量】或者【新品优先】，则直接切换 tab
		if (e.index === state.currentTab) {
			return;
		}

    state.currentTab = e.index;
    state.currentSort = e.sort;
    state.currentOrder = e.order;
		emptyList();
		getList(e.sort, e.order);
	}

	// 点击 tab 的 list 筛选项
	const onFilterItem = (val) => {
    // 如果点击的是当前的筛选项，则直接收起筛选项，不要加载数据
    // 这里选择 tabList[0] 的原因，是目前只有它有 list
		if (state.currentSort === state.tabList[0].list[val].sort
      && state.currentOrder === state.tabList[0].list[val].order) {
			state.showFilter = false;
			return;
		}
    state.showFilter = false;

    // 设置筛选条件
		state.curFilter = val;
		state.tabList[0].name = state.tabList[0].list[val].label;
		state.currentSort = state.tabList[0].list[val].sort;
		state.currentOrder = state.tabList[0].list[val].order;
		// 清空 + 加载数据
    emptyList();
		getList();
	}

	async function getList() {
		state.loadStatus = 'loading';
		const { code, data } = await SpuApi.getSpuPage({
      pageNo: state.pagination.pageNo,
      pageSize: state.pagination.pageSize,
			sortField: state.currentSort,
			sortAsc: state.currentOrder,
			categoryId: state.categoryId,
			keyword: state.keyword,
		});
    if (code !== 0) {
      return;
    }
    state.pagination.list = _.concat(state.pagination.list, data.list)
    state.pagination.total = data.total;
    state.loadStatus = state.pagination.list.length < state.pagination.total ? 'more' : 'noMore';
    mountMasonry();
	}

	// 加载更多
	function loadMore() {
    if (state.loadStatus === 'noMore') {
      return;
    }
    state.pagination.pageNo++;
    getList(state.currentSort, state.currentOrder);
	}

	onLoad((options) => {
		state.categoryId = options.categoryId;
		state.keyword = options.keyword;
		getList(state.currentSort, state.currentOrder);
	});

	// 上拉加载更多
	onReachBottom(() => {
		loadMore();
	});
</script>

<style lang="scss" scoped>
	.goods-list-box {
		width: 50%;
		box-sizing: border-box;

		.left-list {
			margin-right: 10rpx;
			margin-bottom: 20rpx;
		}

		.right-list {
			margin-left: 10rpx;
			margin-bottom: 20rpx;
		}
	}

	.goods-box {
		&:nth-last-of-type(1) {
			margin-bottom: 0 !important;
		}

		&:nth-child(2n) {
			margin-right: 0;
		}
	}

	.list-icon {
		width: 80rpx;

		.sicon-goods-card {
			font-size: 40rpx;
		}

		.sicon-goods-list {
			font-size: 40rpx;
		}
	}

	.goods-card {
		margin-left: 20rpx;
	}

	.list-filter-tabs {
		background-color: #fff;
	}

	.filter-list-box {
		padding: 28rpx 52rpx;

		.filter-item {
			font-size: 28rpx;
			font-weight: 500;
			color: #333333;
			line-height: normal;
			margin-bottom: 24rpx;

			&:nth-last-child(1) {
				margin-bottom: 0;
			}
		}

		.filter-item-active {
			color: var(--ui-BG-Main);
		}
	}

	.tab-item {
		height: 50px;
		position: relative;
		z-index: 11;

		.tab-title {
			font-size: 30rpx;
		}

		.cur-tab-title {
			font-weight: $font-weight-bold;
		}

		.tab-line {
			width: 60rpx;
			height: 6rpx;
			border-radius: 6rpx;
			position: absolute;
			left: 50%;
			transform: translateX(-50%);
			bottom: 10rpx;
			background-color: var(--ui-BG-Main);
			z-index: 12;
		}
	}
</style>